Mean (SE) plasma antioxidant capacity (TEAC) and protein thiols in healthy non-smokers, smokers, and patients with COPD
| Subjects | Antioxidant capacity | Protein thiols (mM) |
| Healthy non-smokers (n = 31) | 1.31 (0.11) | 0.56 (0.06) |
| Healthy smokers (n = 82) | 0.87 (0.04)** | 0.39 (0.03)2-150 |
| Current smokers (n = 31) | 0.90 (0.05)** | 0.42 (0.03)2-150 |
| Ex-smokers (n = 51) | 0.83 (0.04)** ,NS | 0.38 (0.03)2-150 ,NS |
| COPD (n = 95) | 0.81 (0.03)** | 0.40 (0.03)2-150 |
| Current smokers (n = 25) | 0.78 (0.05)** | 0.43 (0.04)2-150 |
| Ex-smokers (n = 70) | 0.84 (0.02)** ,NS | 0.38 (0.02)2-150 ,NS |
↵2-150 p<0.01, **p<0.001 compared with healthy non-smokers and non-significant (NS) compared with current smokers.